Nis donovan



L. OH'ARA.

(No Model.)

LIPTING JACK.

Patented May 12, 1885.

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I Illl'l NTTED STATES PATENT OFFICE.

LEWIS OHARA, OF OSWEGO, NEW YORK, ASSIGNOR OFONE-HALF 'IO DEN- v NIS DONOVAN, OF SAME PLACE.

LlFTlNG-JACK.

SPECCATION forming part of Letters Patent No. 317,951, dated May 12, 1885.

Application flied March 18, 1885.

(No model.)

jacks in which a screw is employed as the lift-y ing-power.

rIhe invention consists in an improved construction and combination of the constituent members of a jack possessing superior efficiency, stability,and convenience o'f operation.

The invention is fully illustrated in the annexed drawings, wherein Figure lis a side elevation of my liftingjack. Fig. 2 is a vertical transverse section ofthe same, and Fig. 3 is a horizontal transverse section on line y y, Fig.1.

Similar letters of reference indicate corresponding parts. 1

S represents the screw which is to furnish the lifting-power.

A represents the base of the jack provided with a screw-threaded socket, in which the lower end of screw S works, and B designates lthe top bearing, which may be either pivoted on the upper end of the screw in the usual manner or provided with a screw-threaded socket by which it is connected with the upper end of the screw S, having screw-threads running in opposite direction from those on the lower end of the screw. By the employment of this right-and-left screw, in connection with the screw-threaded base A and top bearing,B, the movement of the top bearing is accelerated to twice the speed of an ordinary screw-jack.

On the central portion of the screw S is rigidly secured a horizontal ratchet-disk, r, and above this disk is a collar, c, loosely connected with the screw, so as to allow it to freely turn thereon. Said collar is provided. with ascrewthreaded socket, a, standing radially in relation to the screw. With this socket is detachably connected a lever, Z, having its ends screw-threaded and entering the aforesaid socket. Back of the screw-threaded portion of the lever a smooth neck, n, and a shoulder, o, back of said neck, are formed on said lever.

On the neck of thelever Z is pivoted apawl, p, provided with an eye, c, which embraces the neck n and abuts against the shoulder o thereof, and against the exterior of the socket a, as illustrated in Fig. 2 of the drawings. The said pawl is of such a form as to adapt it to engage with the ratchet r, and can be swung claim as new, and desire to secure by-Letters Patent, is-

In combination with the screw S and ratchetl r attached thereto, the collar c, loosely connected with the screw and provided with the screw-threaded socket a, the lever Z, having a screw-threaded end detachably connected with the socket a, and formed with the smooth neck n and shoulder o, back of the screwthreaded portion, and the pawl p, provided with the eye e, embracing the neck n and abutting against the shoulder o and exterior of the socket a, substantially as described and shown.

In testimony whereof I have hereunto signed my name and aflixed my seal, in the presence of two attesting witnesses, at Syracuse, in the county of Onondaga, in the State of New York, this 9th day of March, 1885.

LEVIS OHARA. [L s] Witnesses:

WM. C. RAYMOND, F. H. Gines. 

